尿素配施氯化铵对菜心产量及其品质的影响

利用盆栽试验，研究尿素配施不同比例的氯化铵对菜心硝酸盐积累的影响，结果表明：随着尿素配施氯化铵比例的增加，菜心氯含量增加，硝酸盐含量下降，而全N含量、叶绿素含量和收获前的产量变化不大。     

旱垂柳转录组测序及赤霉素在垂枝形成中的作用

垂枝作为特殊的林木形态结构,因形态优美在全世界被广泛用于绿化和园林景观而成为研究热点。国内外对垂枝植物的研究表明赤霉素在垂枝形成中起作用,但是垂枝形成的分子背景研究仍比较缺乏。本研究以旱垂柳(Salix matsudana var. pseudo-matsudana)的垂枝为研究对象,通过对旱垂柳在不同生长发育时期的叶片、茎尖和茎基部进行了转录组和数字表达谱测序研究,共获得71 474个Unigenes序列。将Unigenes与COG和KEEG数据库比对,与转录和信号转导机制相关的基因在旱垂柳中高度富集,最终确定8 359个差异表达的基因,其中427个基因与激素相关。进一步分析赤霉素相关基因得出,主要参与2条赤霉素合成途径,具有生物活性的GA4是合成途径中的主要产物,而且GA4在枝条中的含量显著高于GA1和GA3。参与赤霉素信号转导途径中的GID1B在旱垂柳中上调表达,以及在G1和G4生长期的表达量高于其他时期,而DELLA蛋白GAI在G2生长期以后下调表达,GID1B和GAI在旱垂柳的垂枝生长过程中可能起非常重要的作用。这些研究结果将有助于探索赤霉素在旱垂柳垂枝形成中的分子作用,可为林木形态的遗传改良提供基础理论依据。     

Sodium bicarbonate reduces postharvest decay development on melons

Sodium bicarbonate (SBC) inhibited in vitro mycelial growth of A. alternata, Fusarium spp. and R. stolonifer. SBC action was fungistatic rather than fungicidal. Coating commercially harvested ‘Galia’ and ‘Ein-Dor’ melons with wax containing 2% SBC reduced decay incidence after storage and shelf life simulation by four to seven-fold, to a commercially acceptable level of 6–7%, compared to untreated or waxed-treated controls. This treatment also maintained the fresh and blemish-free appearance of the fruit at harvest. Higher concentrations of SBC (3%) were phytotoxic and significantly reduced general fruit appearance. A trial shipment by sea transport to Europe demonstrated that 2% SBC incorporated into a wax coating maintained the marketability of ‘Galia’ melon fruits compared to that of untreated fruit. SBC can be an alternative biocide to the fungicide imazalil, thus eliminating unwanted residues on melon fruits.     

A Spot Price Model with Var Cost

This paper has applied the var cost to the theory of spot price.An augmented Lagrange method is employed to develop the exact model of spot price of active power and reactive power,and the physical means of Lagrange multipliers are explained.The numerical examples are given to demonstrate the validity of the proposed model.     

新化水酒辣蓼草酒药工艺技术研究

以大米为原料,在酒药制作过程中添加辣蓼草,以糖化力和发酵力为评价指标,通过单因素试验和正交试验,探讨了辣蓼草添加量、种曲添加量、培曲时间对新化水酒酒药品质的影响,筛选出新化水酒辣蓼草酒药的最佳制作工艺条件。结果表明,新化水酒辣蓼草酒药的最佳制作工艺条件为：辣蓼草添加量6%,种曲添加量5%,培曲时间60 h,在此工艺条件下制得的酒药糖化力和发酵力分别为1 443 U/g和53.4 g/100 g。     

结球甘蓝的离体快繁技术研究

以结球甘蓝无菌苗的胚轴和子叶为材料，几乎不生长愈伤组织，分化出不定芽。不定芽在添加6-BA的MS培养基上增殖很快，适宜的生根培养基为1/2MS+IBA0.5mg/L+ NAA0.1mg/L。通过增加培养基中糖和琼脂粉的用量，提高培养时的光照强度等有效控制了玻璃苗的产生。     

Carbon Isotope Discrimination, Leaf Ash Content and Grain Yield in Bread and Durum Wheat Grown under Full-Irrigated Conditions

Integrative physiological criteria, such as carbon isotope discrimination (Δ) and (mineral) ash content (m_a) have been found to be very useful, under drought conditions, to elucidate the association between yield gains and variation of photosynthesis‐related traits and orientate future breeding efforts. Information on this association is scarce under irrigated conditions. The relationships between Δ, m_a and yield were studied in bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L. var. durum) under optimal (drip) irrigation in the arid conditions of north‐west Mexico. Carbon isotope discrimination was analysed on leaves at booting stage and anthesis and on grain at maturity, whereas ash content was measured on the flag leaf at anthesis and maturity. At anthesis, there were differences between bread and durum wheat during grain filling for Δ, but not for m_a. No relationship was found between grain yield and Δ. Leaf ash content at anthesis and maturity showed a broad variability within each species and were associated with grain yield. These results suggest that ash content in leaves could be also used as predictive criteria for yield not only under drought, but also under irrigated conditions, particularly when evaporative demand is high.     

黑胫病菌诱导的烟草SSH文库构建及其分析

黑胫病是危害严重的世界性烟草主要病害之一,探究烟草对黑胫病的抗病机制,可以为该病的综合防治提供理论依据。本研究以烟草黑胫病抗性品种革新3号为材料,利用黑胫病0号生理小种诱导其水平抗性,分别在接种后0.5、1、3、6、10和16 d取样,通过抑制差减杂交技术(SSH)构建cDNA文库,获得了960个阳性克隆。利用反向Northern斑点杂交技术对其中240个阳性克隆进行杂交筛选,筛选出57个表达差异明显的基因,序列拼接后获得33条高质量EST,测序及其比对分析表明,革新3号对烟草黑胫病抗性相关基因主要涉及抗病防卫、光合作用、信号传导和能量代谢等方面。进一步基因功能分析显示,病程相关PR1b蛋白、半胱氨酸蛋白、延伸因子1-α、α-微管蛋白、细胞色素P450、精胺合成酶、水通道蛋白、过氧化物酶体膜蛋白、甘氨酸延伸因子等可能参与了烟草与黑胫病菌非亲和互作过程。     

Fruit maturity affects the response of apples to heat stress

Quality changes of apple fruit at different maturity stages in response to heat stress were investigated. ‘Jonagold’ and ‘Cortland’ apples at immature (pre-climacteric), commercial harvest maturity (CHM) and post climacteric maturity (PCM, CHM plus 4 weeks) were harvested and held at 46 °C for 0, 4, 8, or 12 h. Following treatments, fruits were stored in air at 0 °C and evaluated after 0, 1, 2, or 3 months. Quality indices including peel and flesh browning, firmness, titratable acidity, soluble solids, chlorophyll fluorescence (CF), and ethanol production were measured. Results indicated that different cultivars and maturities affected the fruit's resistance to heat stress. ‘Jonagold’ was more resistant to heat stress than ‘Cortland’. Fruit at PCM were most sensitive to heat stress, followed by fruits at CHM and immature stages. When ‘Jonagold’ apples at immature and CHM stages were held at 46 °C for 12 h and then stored for 3 months, flesh browning ratings were negligible compared with 1.4 or 2.9, respectively in ‘Cortland’. Flesh browning rating increased to 1.4 or 4.5 in PCM ‘Jonagold’ held at 46 °C for 8 or 12 h and then stored for 3 months while it was 4.9 or 5.0, respectively, in ‘Cortland’. Heat treatment-induced flesh injury was associated with a decrease in CF. After fruit were exposure to 46 °C for 12 h and then stored for 3 months, Fv/Fm was reduced by 13%, 30%, and 55% in ‘Jonagold’ at immature maturity, CHM and PCM, respectively, while it was reduced by 51%, 58% and 75%, respectively, in ‘Cortland’. Heat stress also caused a decrease in fruit titratable acidity, but had no effect on soluble solids contents. The 8 or 12 h heat treatment resulted in an increase in ethanol production, which was greatest in PCM apples.